Adopted in 1793, the Anti-Injunction Act (AIA) has come to symbolize the early republic’s concern with protecting state court autonomy from an overbearing federal judiciary. Most modern observers encounter the AIA and its seemingly absolute prohibition of “writs of injunction” to stay state court proceedings as an absolute barrier to federal interposition. Whatever their view of the rise of judge-made exceptions to the AIA, all agree that the origins of the Act were, as the Supreme Court itself observed, “shrouded in obscurity.”

In an effort to peel back the obscuring shroud, we return to an eighteenth century world in which separate courts of law and equity exercised concurrent jurisdiction over the same dispute and courts of equity secured their role through the almost-routine issuance of injunctions to stay proceedings at law. An excellent example of such stay litigation, and the likely trigger of the AIA’s adoption, unfolded in the North Carolina state and federal courts, as the Pennsylvania-based financier and founder Robert Morris attempted to stay the enforcement of an adverse state court judgment.

Far from obscure, we find that the language of the AIA was likely drafted to address the specific problem of federal-state concurrency laid bare in Morris’s case, Morris v. Allen. By limiting its restriction to “writs of injunction,” the AIA barred original federal interposition but left the federal courts free to issue ancillary stays to protect federal jurisdiction and federal decrees. Reclaiming this lost distinction between original and ancillary injunctive relief calls for a fundamental reconsideration of the place of the 1793 Act in the legislative output of the early republic. Far from the absolute bar that it later became in the hands of twentieth century jurists such as Felix Frankfurter, the 1793 Act was drafted to provide a nuanced solution to a very real problem of federal-state judicial relations that the merger of law and equity has since obscured from view.